1. Field of the Invention
The present invention relates to a stator vane for a gas turbine.
2. Description of the Related Art
For a vane to which load is heavily applied, a flow of fluid streaming near an end wall of the vane, that is, a secondary flow, at a cross section perpendicular to a main flow of gas, is augmented, irrespective of whether the end wall is positioned at an inner circumferential side of the vane or a casing side of a turbine. The augmentation of the secondary flow reduces a flow rate of the fluid streaming near the end wall, correspondingly increases a flow rate of the fluid streaming in a vicinal region of a mean-diametral section of the vane, and thus further increases the load of the vane. As a result, the increase in vane load is known to induce an increase in total pressure loss.
A method has been proposed which forms end wall surfaces into an axially asymmetrical shape to prevent total pressure loss from increasing at such a vane cascade that is heavily loaded. Axially asymmetrical shaping reduces the total pressure loss at the vane cascade. A vane formed with a curved surface including a pair of surfaces, one convexed with respect to an end wall surface, at a pressure surface side, and one concaved with respect thereto, at a suction surface side, is proposed as an example in U.S. Pat. No. 2,735,612.